Bag-making machine

ABSTRACT

The disclosure is of improvements in a bag-making machine characterised in that for the manufacture of bags of great length, the bag lengths are folded before welding of the bag bottom, and in that the device for cooling the weld is constituted by a plurality of bars presented in the form of a belt which during a certain time accompanies the accumulating drum and therefore the bags.

United States Patent 1 Class [451 July 8,1975

[ BAG-MAKING MACHINE [75] Inventor: Jean Class, Strasbourg, France [73] Assignee; Les Ateliers de Constructions Mecaniques C. & A, Holweg- S.A'., Strasbourg, France [22-] Filed: Sept. 20, 1972 [21] Appl. No.: 290,750

[30] Foreign Application Priority Data 156/510, 256, 443, 583; 53/39, 179; 93/33 H, 62, 35 VL; 62/3 [56] References Cited UNITED STATES PATENTS 1,713,243 5/1929 Swab 93/62 2,738,828 3/1956 Hammer 156/290 2,952,299 9/1960 Finke 156/498 3,038,833 6/1962 Glover 156/498 3,079,847 3/1963 Polipori, J1. 93/62 3,248,889 5/1966 Zimmermann. 62/3 3,367,261 2/1968 Kashiwagi 156/498 3,499,817 3/1970 Havens et a1. 156/498 3,622,421 11/1971 COOk 156/290 3,635,037 1/ 1972 Hubert 62/3 3,643,555 2/1972 Ehlscheid 93/62 3,655,486 4/1972 Hagino et a1. 156/498 3,723,230 3/1973 Troutner 156/580 3,762,282 10/1973 Van Der Meulen 93/33 H 3,773,596 11/1973 K310 156/510 Primary ExaminerCharles E. Van Horn Assistant Examiner-Basil J. Lewris Attorney, Age'nt, or F irm--Young & Thompson [57] ABSTRACT The disclosure is of improvements in a bag-making machine characterised in that for the manufacture of bags of great length, the bag lengths are folded before welding of the bag bottom, and in that the device for cooling the Weld is constituted by a plurality of bars presented in the form of a belt which during a certain time accompanies the accumulating drum and therefore the bags".

Claims, 3 Drawing Figures mm-mmm 8 1915 I 8, 888.884

sum 1 I /I II J am FIG. 1

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BAG-MAKING MACHINE INTRODUCTION AND BACKGROUND OF THE INVENTION The present invention makes various improvements in a rotary machine for the continuous manufacture of bags of plastic or the like material.

On the one hand it permits the manufacture of long bags without increasing the dimensions of the machine and thus its price, by means of a device for folding the lengths intended to become the said bags, and on the other hand it improves the rapid cooling of the welds in order to permit sound manufacture at a high rate.

In a previously proposed machine, the maximum length of the bag is limited by the distance or area separating two consecutive sealing grippers, so that if it is intended to manufacture very long bags, such for example as manure bags, one is obliged to increase the diameter of the drum and the dimensions of all the elements cooperating with it. The result is an enormous machine of prohibitive cost. Moreover by reason of their actual dimensions, the ejection of the said bags or packets of bags would require a great reduction of the production rate, and the manipulation of the packets of bags of large dimensions would be very difficult.

Thus the invention has the purpose of remedying these drawbacks and of permitting, by a single or multiple fold, of manufacturing bags the length of which is noticeably greater than the distance separating the sealing grippers on a machine of normal dimensions. According to the previous proposal the length is welded at its rearward part, and according to the present invention it will previously be folded and presented with the fold foremost to the welding drum, where it is held by straps.

By means of a single fold, deducting the overhanging part for the weld, it is possible to double the length of the bags, and it. is possible to treble or quadruple it by multiple folds obtained in accordance with known methods.

As regards the previously proposed device for the cooling of the welds, its perfect operation has been observed in normal working, but it was noted that it was insufficient for high speed machines or when the welded material, by reason of its thickness, has too great an enthalpy. This is due to the fact that the cooling bar has only tangential contact with the weld and this takes place only during a very short time. The samll quantity of water or cooling liquid evaporates rapidly, the weld is not sufficiently cooled, and on gathering of the completed bags these stick together, which compels reduction of the working rate of the machine.

BRIEF SUMMARY OF THE INVENTION According to the new method of cooling in accordance with the invention, cooling by water in direct contact with the weld is preferably still utilised, but in such manner that contact is very long. This new device permits either of eliminating the old device or of retaining it in order to have a supplementary cooling capacity. The invention also provides a machine for the manufacture of bags of great length wherein the bag lengths are folded, before welding of the bag bottom, and the device for cooling the weld is constituted by a plurality of bars presented in the form of a belt which during a certain time accompanies the accumulating drum and therefore the bags.

FURTHER DESCRIPTION AND ADVANTAGES OF THE INVENTION According to a variant of the invention, the bars which transport the cooling liquid can be replaced by electric Peltier effect cooling plates.

Further features of the invention are set forth in the following description given with reference to the accompanying drawings, which description and drawings are given only by way of non-limitative examples of the invention which includes all variants thereof.

BRIEF DESCRIPTION OF THE VIEWS IN THE DRAWINGS In the drawings:

FIG. 1 is a perspective view showing the path of a length arriving on the welding drum according to a previous proposal;

FIG. 2 is a perspective view showing the arrival of a length on the welding drum after folding, according to the invention, and

FIG. 3 is an elevation showing a folding device adapted to the first transfer drum and the new cooling device.

DETAILED DESCRIPTION OF WHAT THE DRAWINGS SHOW In departure from FIG. 1, in which there is represented the path of a bag length 200 which is transported by means of a first transfer drum 66 as indicated by the dotted lines towards the welding drum 21 which imparts a weld 201 to its rearward part, FIG. 2 represents a section 200 arriving as previously but which, in accordance with the present invention, before being introduced to the welding drum 21 is subjected to a transverse fold 202 so that its ends are staggered by a length x selected according to the positioning of the weld 201, which will be effected on the drum 21 on one of the ends of the said length.

The general arrangement of the elements as represented in FIG. 3 is in conformity to some extent with a previous proposal, but the transfer drum 66 is completed by a gripper device of which one gripper 203 is fixed while the other 204 is movable. The drum 66 cooperates with a drum 205 the outer shell of which is pierced with a series of holes 206 which are connected to a suction pump. The drum 205 likewise comprises a folding blade 207 which cooperates with the grippers 203 and 204 of the drum 66.

The forward part of the length 200 is sucked by means of the holes 206. At the position selected for the effecting of the fold 202, the blade 207 engages the said length between the grippers 203 and 204, which close and strongly hold the folded length, entraining it downwards in the course of the rotation of the drum 66. The forward part, previously grasped by the drum 205, now slides on the latter. On arrival at the point of tangents T between the drums 21 and 66, the movable gripper 204 opens and engages the folded length 200 between the welding drum 21 and the straps 1 1. The other manufacturing operations take place in a manner previously proposed. This form of embodiment does not limit the invention which includes all variants thereof and in particular those where by known means, by

means of consecutive folds, the length can be folded several times according to its longitudinal dimension.

The present invention thus permits, by means of a single or multiple folding of the lengths, after their cutting and before any other manufacturing operation, of manufacturing bags of plastic or other material on a rotary machine, it being possible for the said bags to have a length much greater than than of the area determining the length of folded bags.

Moreover reception of folded bags or packets of folded bags at the edges of the machine is greatly simplified and saves labour.

According to another characteristic of the present invention a new cooling device is provided which is represented in FIG. 3. By way of example this is placed beneath the accumulating drum 38, but by way of variant it could equally be placed on the second transfer drum 35 without any change in its operation. On a pair of chains 208 having angled side plates, guided by a plurality of chain wheels 209, there are fixed preferably flat or T-shaped bars 210 in sufficient number to form a kind of belt which accompanies the accumulating drum 38 in the course of its rotation. This belt is moved by means of gearing (not shown) at a linear speed equal to the peripheral speed of the drum 38. The bags accumulate on the drum 38 and are held on its lower part by the said belt. At regular intervals corresponding to the distance between two consecutive packets of bags, the corresponding bars are raised and lined with a material 211 capable of retaining the cooling liquid 212, such as sponge rubber or felt for example. The position of the bars lined with the material 211 is regulated in relation to the drum 38 so that they come into contact with the weld and maintain this contact over the whole length of the are A, permitting of ensuring cooling over a very long path.

- The cooling liquid 212 is contained in a vessel 213 and is distributed to the bars 210 by means of a roller device 214.

The invention is not limited to the example given for its realisation but includes all variants thereof and especially that where the material 211 is replaced by electric Peltier effect cooling plates, permitting of cooling without any liquid.

The invention also comprises any machine in accordance with the description of the invention or realised by analogous means.

What is claimed is:

1. In a machine for the manufacture of bags from thermoplastic material, comprising means for advancing a continuous tube of thermoplastic material, means for severing lengths from said tube, a welding drum on which one end of each said length is heat-sealed closed along a transverse weld line, and a further drum about which said lengths pass after leaving said welding drum; the improvement comprising means disposed between said severing means and said welding drum for folding said lengths about at least one transverse fold line, and an endless belt that coacts with said further drum so that said lengths pass between said belt and said further drum, said belt having thereon a plurality of spaced bars that contact the heat-sealed ends of said lengths along said transverse weld line, and means to cool said bars.

2. A machine as claimed in claim 1, said folding means comprising a folding blade for forming a transverse fold in said lengths between the forward and rear ends of said lengths with respect to the direction of movement of said lengths by said advancing means, and suction means for retarding the forward end of the lengths thereby to fold said forward end back on said rearward end upon continued movement of said lengths by said advancing means.

3. A machine as claimed in claim 2, said folding means comprising a pair of drums between which said lengths pass, one of said drums carrying said folding blade and said suction means and the other of said drums carrying movable gripper means that releasably grasp the fold formed by said folding blade.

4. A machine as claimed in claim 1, and material on said bars for retaining a cooling liquid, and means to apply a cooling liquid to said material on said bars.

5. A machine as claimed in claim 4, said liquidapplying means comprising a vessel with cooling liquid with fountain roller means therein. 

1. IN A MACHINE FOR THE MANUFACTURE OF BAGS FROM THERMOPLASTIC MATERIAL, COMPRISING MEANS FOR ADVANCING A CONTINUOUS TUBE OF THERMOPLASTIX MATERIAL, MEANS FOR SEVERING LENGTHS FROM SAID TUBE, A WELDING DRUM ON WHICH ONE END OF EACH SAID LENGTH IS HEAT-SEALED CLOSED ALONG A TRANSVERSE WELD LINE, AND A FURTHER DRUM ABOUT WHICH SAID LENGTHS PASS AFTER LEAVING SAID WELDING DRUM, THE IMPROVEMENT COMPRISING MEANS DISPOSED BETWEEN SAUD SEVERING MEANS AND SAID WELDING DRUM FOR FOLDING SAID LENGTHS ABOUT AT LEAST ONE TRANSVERSE FOLD LINE, AND AN ENDLESS BELT THAT COACTS WITH SAID FURTHER DRUM SO THAT SAID LENGTHS PASS BETWEEN SAID BELT AND SAID FURTHER DRUM, SAID BELT HAVING THEREON A PLURALITY OF SPACED BARS THAT CONTACT THE HEAT-SEALED ENDS OF SAID LENGTHS ALONG SAID TRANSVERSE WELD LINE, AND MEANS TO COOL SAID BARS.
 2. A machine as claimed in claim 1, said folding means comprising a folding blade for forming a transverse fold in said lengths between the forward and rear ends of said lengths with respect to the direction of movement of said lengths by said advancing means, and suction means for retarding the forward end of the lengths thereby to fold said forward end back on said rearward end upon continued movement of said lengths by said advancing means.
 3. A machine as claimed in claim 2, said folding means comprising a pair of drums between which said lengths pass, one of said drums carrying said folding blade and said suction means and the other of said drums carrying movable gripper means that releasably grasp the fold formed by said folding blade.
 4. A machine as claimed in claim 1, and material on said bars for retaining a cooling liquid, and means to apply a cooling liquid to said material on said bars.
 5. A machine as claimed in claim 4, said liquid-applying means comprising a vessel with cooling liquid with fountain roller means therein. 